Environmental Contamination by Heavy Metals

The environment and its compartments have been severely polluted by heavy metals. This has compromised the ability of the environment to foster life and render its intrinsic values. Heavy metals are known to be naturally occurring compounds, but anthropogenic activities introduce them in large quantities in different environmental compartments. This leads to the environment’s ability to foster life being reduced as human, animal, and plant health become threatened. This occurs due to bioaccumulation in the food chains as a result of the nondegradable state of the heavy metals. Remediation of heavy metals requires special attention to protect soil quality, air quality, water quality, human health, animal health, and all spheres as a collection. Developed physical and chemical heavy metal remediation technologies are demanding costs which are not feasible, time-consuming, and release additional waste to the environment. This chapter summarises the problems related to heavy metal pollution and various remediation technologies. A case study in South Africa mines were also used

The relationship between the expressed meaning of work and job satisfaction in a group of school educators.

Thesis (M.Soc.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.The study investigated the relationship between the expressed meaning and value of work and satisfaction of a group of school educators. The main objective of the current study was to explicate what teachers' express as making work meaningful, and what it is that gives them satisfaction as school teachers and also how that perception affects their performance. The relationship between the expressed meaning of work and job satisfaction will be dealt with, and in attempting to explain the concept of Job satisfaction, theories such as those by Herzberg and Maslow were employed to aid in answering the above mentioned questions. Some of the factors which have been identified in the literature and are seen as contributors of job satisfaction of teachers are motivation, workplace conditions, support from learners and their parents, job security as well as interpersonal relations and good social standing with other colleagues. While there may be no evidence to draw a causal relationship between pay, meaning of work and job satisfaction, pay has been widely studied in relation to job satisfaction. It is associated with achievement and recognition by one's peers, so the relationship between money and job satisfaction and pay satisfaction was explored in an attempt to find a correlation in that job and life satisfaction. The study was unable to find a concrete basis to conclude that teachers from one type of school were more satisfied than teachers from another type of school, based on the two types of schools studied in the research. It was also discovered using "The need- satisfaction in work scale", that white teachers seem to score higher on Independence, recognition and on economic and social security, but black teachers have scored higher on self-expression. Just like many other employees, teachers also desire decent salaries and benefits, suitable working conditions, recognition, and promotion opportunities and contrary to popular belief, the study found that many teachers are happy with their professional roles as teachers

Computational and experimental study for the desalination of petrochemical industrial effluents using direct contact membrane distillation

Abstract The petrochemical, mining and power industries have reacted to the recent South African water crisis by focussing on improved brine treatment for water and salt recovery with the aim of achieving zero liquid effluent discharge. The purpose of this novel study was to compare experimentally obtained results from the treatment of synthetic NaCl solutions and petrochemical industrial brines such as spent ion exchange regenerant brines and reverse osmosis (RO) brines to the classical well-known Knudsen diffusion, molecular diffusion and transition predictive models. The predictive models were numerically solved using a developed mathematical algorithm that was coded using MATLAB® software. The impact of experimentally varying the inlet feed temperature on process performance of the system is presented here and compared to simulated results. It was found that there was good agreement between the experimentally obtained results, for both the synthetic NaCl solution and the industrial brines. The mean average percentage error (MAPE) was found to be 7.9% for the synthetic NaCl solutions when compared to the Knudsen model. The Knudsen/molecular diffusion transition theoretical model best predicted the performance of the membrane for the industrial spent ion exchange regenerant brine with a mean absolute percentage error (MAPE) of 13.3%. The Knudsen model best predicted the performance of the membrane (MAPE of 10.5%) for the industrial RO brine. Overall, the models were able to successfully predict the water flux and can be used as potential process design tools

Blockchain-Enabled Vaccination Registration and Verification System in Healthcare Management

Client-server-based healthcare systems are unable to manipulate a high data volume, prone to a single failure point, limited scalability, and data integrity. Particularly, several measures introduced to help curb the spread of Covid-19 were not effective and patient records were not adequately managed and maintained. Most vaccination-proof certificates were forged by unauthorized parties and no standard verification medium exists. Therefore, this paper proposes a blockchain-enabled vaccination management system (VMS). VMS utilizes smart contracts to store encrypted patients record, generate vaccination certificates, and verify the legitimacy of the certificate using a QR code. VMS prototype is implemented using Ethereum, a public blockchain and simulations performed based on Apache JMeter and Hyperledger Caliper to assess its performance in terms of throughput, latency and response time, and the average time per transaction. Results show VMS achieved an average: response time of 132.24 ms, the throughput of 379.89 tps, latency of 204.60 ms, and time of transactions is 10s-12s for 1000 transactions. Also, its comparison with the centralized database shows the traditional database’s effectiveness in transaction processing but lacks data privacy and security strengths. We, therefore, recommend the use of blockchain in the healthcare system and other related sectors such as elections, and student records management to ensure data privacy and security and rid the system of a single point of failure